Try CRYSTAL

What you can do with the demo version

A CRYSTAL14 evaluation copy is available free of charge for Linux and Windows operating systems. All functionalities of the full version are active, the only limit is the number of atoms, restricted to 20 per primitive cell. CRYSCOR09 is also part of the CRYSTAL14 demo version with the limit of 3 atoms per primitive cell.
For a quick introduction to CRYSTAL input and output a guided "CRYSTAL tour" is suggested.

Here below some example of systems that can be studied with the evaluation version of CRYSTAL14.

Minimal basis set Extended basis set
Beryllium bulk Beryllium bulk
MgO bulk MgO bulk
NiO bulk - ferromagnetic phase NiO bulk - ferromagnetic phase
Si bulk Si bulk
Diamond Diamond
Graphite monolayer  
  MgO (001) surface - monolayer
  CO on MgO (001) surface - monolayer
(SN)x polymer  
  Urea bulk
Here CRYSCOR Test Jobs

How to get the demo version

To get an evaluation copy you first have to register, you'll find the download link in your personal account page.